device/vlan: update hw address also during prepare phase

The hardware address of a VLAN must be kept aligned with the one of
its parent device, and we already used a signal in NMDeviceVlan to
catch changes in parent address and update the VLAN device
accordingly.

But this didn't work in all cases because the change might happen
after the VLAN gets created but before we register the signal, so it
is necessary to add further checks to enforce the alignment during the
device activation.

https://bugzilla.redhat.com/show_bug.cgi?id=1325752

1 files changed, 30 insertions, 21 deletions

diff --git a/src/devices/nm-device-vlan.c b/src/devices/nm-device-vlan.c
index 4d606e9d82..ef30bbeb74 100644
--- a/src/devices/nm-device-vlan.c
+++ b/src/devices/nm-device-vlan.c
@@ -80,14 +80,14 @@ parent_state_changed (NMDevice *parent,
 }
 
 static void
-parent_hwaddr_changed (NMDevice *parent,
-                       GParamSpec *pspec,
-                       gpointer user_data)
+parent_hwaddr_maybe_changed (NMDevice *parent,
+                             GParamSpec *pspec,
+                             gpointer user_data)
 {
 	NMDeviceVlan *self = NM_DEVICE_VLAN (user_data);
 	NMConnection *connection;
 	NMSettingWired *s_wired;
-	const char *cloned_mac = NULL, *new_mac;
+	const char *new_mac, *old_mac;
 	NMSettingIPConfig *s_ip6;
 
 	/* Never touch assumed devices */
@@ -100,23 +100,26 @@ parent_hwaddr_changed (NMDevice *parent,
 
 	/* Update the VLAN MAC only if configuration does not specify one */
 	s_wired = nm_connection_get_setting_wired (connection);
-	if (s_wired)
-		cloned_mac = nm_setting_wired_get_cloned_mac_address (s_wired);
+	if (s_wired) {
+		if (nm_setting_wired_get_cloned_mac_address (s_wired))
+			return;
+	}
 
-	if (!cloned_mac) {
-		new_mac = nm_device_get_hw_address (parent);
-		_LOGD (LOGD_VLAN, "parent hardware address changed to %s%s%s",
-		       NM_PRINT_FMT_QUOTE_STRING (new_mac));
-		if (new_mac) {
-			nm_device_set_hw_addr (self, nm_device_get_hw_address (parent),
-			                       "set", LOGD_VLAN);
-			/* When changing the hw address the interface is taken down,
-			 * removing the IPv6 configuration; reapply it.
-			 */
-			s_ip6 = nm_connection_get_setting_ip6_config (connection);
-			if (s_ip6)
-				nm_device_reactivate_ip6_config (NM_DEVICE (self), s_ip6, s_ip6);
-		}
+	old_mac = nm_device_get_hw_address (self);
+	new_mac = nm_device_get_hw_address (parent);
+	if (nm_streq0 (old_mac, new_mac))
+		return;
+
+	_LOGD (LOGD_VLAN, "parent hardware address changed to %s%s%s",
+	       NM_PRINT_FMT_QUOTE_STRING (new_mac));
+	if (new_mac) {
+		nm_device_set_hw_addr (self, new_mac, "set", LOGD_VLAN);
+		/* When changing the hw address the interface is taken down,
+		 * removing the IPv6 configuration; reapply it.
+		 */
+		s_ip6 = nm_connection_get_setting_ip6_config (connection);
+		if (s_ip6)
+			nm_device_reactivate_ip6_config (NM_DEVICE (self), s_ip6, s_ip6);
 	}
 }
 
@@ -141,7 +144,8 @@ nm_device_vlan_set_parent (NMDeviceVlan *self, NMDevice *parent)
 		                                          device);
 
 		priv->parent_hwaddr_id = g_signal_connect (priv->parent, "notify::" NM_DEVICE_HW_ADDRESS,
-		                                           G_CALLBACK (parent_hwaddr_changed), device);
+		                                           G_CALLBACK (parent_hwaddr_maybe_changed), device);
+		parent_hwaddr_maybe_changed (parent, NULL, self);
 
 		/* Set parent-dependent unmanaged flag */
 		nm_device_set_unmanaged_by_flags (device,
@@ -537,6 +541,7 @@ update_connection (NMDevice *device, NMConnection *connection)
 static NMActStageReturn
 act_stage1_prepare (NMDevice *dev, NMDeviceStateReason *reason)
 {
+	NMDeviceVlanPrivate *priv = NM_DEVICE_VLAN_GET_PRIVATE (dev);
 	NMSettingVlan *s_vlan;
 	NMSettingWired *s_wired;
 	const char *cloned_mac;
@@ -555,6 +560,10 @@ act_stage1_prepare (NMDevice *dev, NMDeviceStateReason *reason)
 		nm_device_set_hw_addr (dev, cloned_mac, "set", LOGD_VLAN);
 	}
 
+	/* Change MAC address to parent's one if needed */
+	if (priv->parent)
+		parent_hwaddr_maybe_changed (priv->parent, NULL, dev);
+
 	s_vlan = (NMSettingVlan *) nm_device_get_applied_setting (dev, NM_TYPE_SETTING_VLAN);
 	if (s_vlan) {
 		gs_free NMVlanQosMapping *ingress_map = NULL;